A stereoscopic image may be generated by mixing left and right images having parallax. In the stereoscopic image displayed on a screen, an image having negative parallax appears to protrude out of the screen, and an image having positive parallax appears to be recessed into the screen in comparison with an image having zero parallax.
In reality, even though eye focus is adjusted to the screen, fusion processes of the eyes are varied according to parallaxes of images. Thus, the images may be perceived to be located in front of or behind the screen so that an observer may experience eye fatigue, dizziness, headaches, and so on when the parallax exceeds a fusion range. Moreover, the images may not seem to be natural or realistic, and the observer may see a double image in serious cases.
The parallax of the stereoscopic image is varied based on the separation between left and right cameras and the distance from a lens to an object.
The stereoscopic image has generally been made by a conventional stereoscopic camera in consideration of a single 3D display platform. Thus, stereoscopic images made for a large movie screen having a convergence distance over 10 m may not be suitable for small-size displays such as mobile handsets having a convergence distance under 30 cm. Conversely, stereoscopic images made for small-size displays cannot be displayed on a large movie screen having a long convergence distance. Because the stereoscopic images have been made as one source-one use type images, distribution of stereoscopic video content has been limited, and thus the various content business market has not been active.
Recently, the sizes of flat panel displays such as liquid crystal displays (LCDs) and plasma display panels (PDPs) have become larger. However, the parallax of an object having a large horizontal width may exceed a convergence limit when the display size becomes extremely wide, not only in normal 2D (two-dimensional) viewing conditions but also in stereoscopic imaging. In addition, the parallax may be easily distinguishable in the stereoscopic imaging, and thus the size of a display image has to be considered.
However, a one source multi use (OSMU) type stereoscopic image which is suitable for a small-size display of 2″ to a large movie screen for a theater has not been made until now.